We have:

(1) x²yz = 12      (2) xy²z = 6       (3) xyz² = 18

xyz = = 6
x = 12/6 = 2
y = 6/6 =1
z =18/6 = 3
x+y+z  = (2+1+3)= 6
 

View different answers : Soroban | radagast|Mark Morse